The invention relates to mechanical tool devices useful in maintaining engines, particularly internal combustion aircraft engines.
Aircraft engine maintenance is particularly critical when compared to the maintenance of most engines when it is considered that aircraft engine failure could easily cost human life while automobile or ground vehicle breakdown normally results in mere, albeit aggravating, inconvenience. Accordingly, aircraft engines undergo more frequent, thorough, and precise maintenance procedures than do most other vehicle or other engines.
Troublesome areas for maintenance concern are the exhaust ports and exhaust manifolds of such engines. In order to ensure efficient and safe evacuation of the exhaust gases from the engine, the surface of the engine block surrounding the exhaust ports must be made planar to within a very small degree of tolerance. This facilitates an airtight fit of the exhaust manifold around the exhaust ports with better and safer evacuation of the exhaust gases.
Formerly, the operation of resurfacing, or grinding, this area of the engine block required removing the particular cylinder or cylinders from the engine assembly. This had to be done in order to permit the careful positioning of a grinding tool in such a manner as to carefully and precisely limit its range of motion within the same plane of the desired surface. Only in this manner could the resurfacing function be satisfactorily performed.
Beginning in 1983, the inventor has designed and developed a tool and mount to more easily accomplish this function. The tool in its early stages comprised a means for fastening a mounting apparatus to the manifold surface of an adjacent exhaust port of a particular aircraft engine. From this mounting apparatus were mounted one or more pivoting arms which permitted free movement of a grinding tool within a precise plane.
Approximately ninety percent of all aircraft using internal combustion engines use one of seven standard engines block sizes. These seven engine block sizes are:
1) the Continental, A and C series engine block; PA1 2) the Continental E series engine block; PA1 3) the Continental IO 360 and TSIO 360 engine block; PA1 4) the Continental O 470, IO 470, TSIO 470, TSIO 520, and IO 520 engine block; PA1 5) the Lycoming parallel valve engine block; PA1 6) the Lycoming angle valve engine block; and PA1 7) the Lycoming upstack engine block. Each of these engines has surfaces upon which such a mounting apparatus could be positioned.
What is not now provided, but would be useful is a single mount facilitating the mounting and using of a planing/resurfacing tool or other type device on a wide variety of aircraft engines, such as the seven listed above. If a tool can be devised to fit each of these engines, than it would be helpful to apply the principles to other engines or combinations of engines. It would also be useful to have such a tool and mount apparatus which mounts to the cylinder head of the same cylinder of the desired exhaust port operation.